This invention relates to reefed-typed parachutes, and more particularly to disreefing devices for parachutes using a reefing line to protect the parachute from the forces normally exerted against a parachute opening.
Parachute canopy reefing consists of restricting the mouth of the parachute, to a smaller diameter, usually by a reefing line, during the initial descent to limit the amount of air admitted to the canopy until it is safe to fully open the parachute. This action avoids an excessive buildup of pressure within the parachute which would otherwise cause canopy blowout and a total destruction of the parachute and its load.
Various types of disreefing devices have been designed to fully open the parachute at a predetermined event. Several different structures have been used to reef parachute canopies. In some parachutes, as illustrated in U.S. Pat. No. 3,047,261 a reefing line freely passes through rings along the canopy skirt and connected at its ends to a cutting device. An alternative to a reefing line around the canopy periphery is to install one around the rigging lines, with a severing means severing the reefing line at the desired time. Such a device is employed in U.K. Pat. No. 747,971 where rupturable bands or "reefing ties" are used to restrain the opening of the parachute.